1. Field of the Invention
Aspects of the invention relate generally to power conversion applications. More particularly, aspects are directed to optimization of multi-phase voltage conversion applications.
2. Description of Related Art
Power conversion equipment is used to provide regulated power and a specified load current to a wide variety of devices, including microprocessors used in computers.
In many computer server systems, at least two power conversion stages are cascaded from the initial power source (e.g., wall supply) to the power consuming loads such as individual processing elements. Each power conversion stage has its own efficiency. The larger the number of stages that are cascaded, the lower the overall converter efficiency will be. In other words, each added power conversion stage reduces the overall end-to-end efficiency.
Nonetheless, more than one power conversion stage is often needed. This is because the input voltages from the initial power source may be quite high, e.g., hundreds of volts (AC), and the (DC) output voltages supplied to (consumed) a given load may be 1-5 volts or even a fraction of a volt. Typically, one stage alone cannot provide an implementation with and end-to-end power conversion efficiency greater than 80%. Thus, individual stages with higher efficiencies are employed.
Furthermore, computer server architecture power converter implementations may be designed for a single point of operation, such as one load current, a fixed number of phases, fixed duty cycles of first and second stages, and fixed gate drive voltages. For example, a design may have 85% efficiency at full load, but the efficiency may be substantially less for other load conditions.